Aerobic Reduction of Cytochrome b566 in Pigeon-Heart Mitochondria

In anaerobic, uncoupled pigeon-heart mitochondria treated with oxidizable substrate, the cytochrome b(566) remains largely oxidized. In the presence of antimycin A, addition of oxygen induces a reduction of this cytochrome. The rate of cytochrome b(566) reduction is comparable to and dependent on the rate of cytochrome c(1) oxidation. Kinetic data suggest that either ubiquinone or another donor of similar potential provides electrons for the reduction of cytochrome b(566). It is postulated that the aerobic reduction of cytochrome b(566) is directly related to the energy conservation at site II.     

The chemotherapy of rodent malaria, XXIX DNA relationships within the subgenus Plasmodium (Vinckeia).

The relationships between rodent malarias were examined by means of DNA buoyant density determinations and DNA--DNA hybridization data. Current views of the existence in this group of four species: Plasmodium berghei, P. yoelli, P. vinckei and P. chabaudi were confirmed. The identity of two chloroquine-resistant lines derived from P. berghei N strain was established. One of these, the NS line, was found to be a subspecies of P. yoelii; the implications of this finding are discussed.     

RNF43 is a tumour suppressor gene mutated in mucinous tumours of the ovary

Mucinous carcinomas represent a distinct morphological subtype which can arise from several organ sites, including the ovary, and their genetic characteristics are largely under‐described. Exome sequencing of 12 primary mucinous ovarian tumours identified RNF43 as the most frequently somatically mutated novel gene, secondary to KRAS and mutated at a frequency equal to that of TP53 and BRAF. Further screening of RNF43 in a larger cohort of ovarian tumours identified additional mutations, with a total frequency of 2/22 (9%) in mucinous ovarian borderline tumours and 6/29 (21%) in mucinous ovarian carcinomas. Seven mutations were predicted to truncate the protein and one missense mutation was predicted to be deleterious by in silico analysis. Six tumours had allelic imbalance at the RNF43 locus, with loss of the wild‐type allele. The mutation spectrum strongly suggests that RNF43 is an important tumour suppressor gene in mucinous ovarian tumours, similar to its reported role in mucinous pancreatic precancerous cysts. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

An international effort examining nursing student attitudes toward older people

Variations in culture and heritage can greatly impact an individual's beliefs, practices, and attitudes and may influence healthcare. The purpose of this research was to better understand the attitudes of student nurses toward older adults in the United States and Costa Rica. An exploratory quantitative research design was utilized for this study. Data were collected using the Kogan Old Persons scale from American and Costa Rican pre-licensure nursing students. Results revealed that total scores were very similar between students on the Kogan positive scale and the Kogan negative scale. Half of the individual items revealed significant differences between students of different cultures. Overall, nursing students reported positive attitudes toward older people with individual differences found between nationality and individual items. Understanding cultural variances and commonalities on student nurse attitudes toward older adults is important to the delivery of culturally diverse nursing education and culturally congruent care.     

Acute appendicitis in the developing world is a morbid disease

IntroductionAcute appendicitis in the developing world has a markedly different disease profile to that in the developed world.MethodsA retrospective study was undertaken over a four-year period at a university hospital in South Africa to review the disease spectrum and the clinical outcome of acute appendicitis.ResultsA total of 1,004 patients (54% male, median age: 18 years) with intraoperatively confirmed appendicitis were reviewed. Over half (56%) were from the urban district within the city of Pietermaritzburg and the remaining 44% were from the rural health district. The median duration of illness from onset to definitive care was 4 days. Sixty per cent of appendices were perforated and associated with intra-abdominal contamination. Forty per cent of patients required reoperation to control intra-abdominal sepsis. Ten per cent required admission to the intensive care unit. The median overall length of hospital stay was 5 days. The mortality rate was 1%.Rural patients had a longer median duration of illness (3 vs 5 days, p<0.001) as well as a more advanced disease profile associated with perforation and severe intra-abdominal sepsis (19% vs 71%, p<0.001). Female patients had a longer median duration of illness (3 vs 4 days, p<0.001), were more likely to present with severe intra-abdominal sepsis (31% vs 54%, p<0.001) and were more likely to require a laparotomy (50% vs 73%, p<0.001). The total cost of managing the entire cohort of 1,004 patients over the 4-year period was £2,060,972.ConclusionsAcute appendicitis in South Africa is a serious disease associated with significant morbidity. Late presentation is common. Female and rural patients have the worst clinical outcomes, with significant cost to the health system.     

Activated natural killer cells and interleukin-2 promote granulocytic and megakaryocytic reconstitution after syngeneic bone marrow transplantation in mice

Purified populations of natural killer (NK) cells were obtained from mice with severe combined immune deficiency (SCID). SCID spleen cells were cultured and activated with recombinant human interleukin-2 (rhIL- 2) in vitro. The activated NK cells were then transferred with syngeneic BALB/c bone marrow cells (BMC) and rhIL-2 into lethally irradiated syngeneic recipients to determine their effect on long-term hematopoietic reconstitution. On analysis, the transfer of rhIL-2- activated NK cells along with BMC resulted in significant increases in splenic and BM hematopoietic progenitor cells when compared with those for mice not receiving NK cells. Histologic and flow cytometric analysis showed a marked increase in granulocytic and megakaryocytic lineage cells present in the spleens of the mice receiving activated NK cells. Analysis of the peripheral blood indicated that the transfer of activated NK cells with BMC also significantly improved platelet and total white blood cell counts, with increases in segmented neutrophils. Erythroid recovery was not affected. Finally, lethally irradiated mice receiving activated NK cells and rhIL-2 along with limiting numbers of syngeneic BMC showed a marked increase in survival rate. These results show that the use of populations enriched for activated NK cells after syngeneic BM transplantation (BMT) has a profound enhancing effect on engraftment primarily affecting megakaryocytic and granulocytic cell reconstitution. Therefore, the transfer of activated NK cells and rhIL- 2 may be of clinical use to promote hematopoietic reconstitution after BMT.     

31P NMR study of improvement in oxidative phosphorylation by vitamins K3 and C in a patient with a defect in electron transport at complex III in skeletal muscle.

The bioenergetic capacity of skeletal muscle in a 17-year-old patient with a severe defect in complex III of the electron transport chain has been examined by 31P NMR measurements of the molar ratio of phosphocreatine to inorganic phosphate (PCr/Pi). Resting ratios were 1.3-2.5, which can be compared with roughly 8.6 for a young, normal female control at rest. Quantitative evaluation of the activity of oxidative metabolism was afforded by the rate of recovery of PCr/Pi from exercise and was found to be 2.5% of normal. After administration of menadione and ascorbate, we found a 21-fold increase of the recovery rate relative to the pretherapy value, to within 56% of the recovery rate of the young female control. Thus, NMR examinations of skeletal muscle at rest and in recovery from activity document marked improvement to specific drug therapy in the electron transport capabilities and the ATP synthesis rate of a patient with a deficiency in a cytochrome b-containing complex III. Improvements in functional ability, although not as dramatic as biochemical changes, are also apparent.     

Unusual chest pain syndromes caused by implanted cardiac device leads: a case series

Chest pain can occur after cardiac device lead placement through various mechanisms. Commonly, this is secondary to perforation. We present four cases of unusual chest pain syndromes secondary to device leads with normal function and position without evidence of typical complications. The possible etiologies and management considerations for these cases are discussed.